Electrical cables which are manufactured and delivered in very long single-piece lengths cannot be wound on drums since they would be of excessive size. They are thus stored in storage tanks by means of an operation known as coiling down.
While it is being coiled down, a cable receives a twist of one turn about its longitudinal axis per turn of the coil.
This twist is borne more or less well by the internal structure of the cable which means that efforts are made both to reduce the twisting and to ensure that it is evenly distributed. To reduce the twisting, the average diameter of the coil turns is increased. To distribute the twist more evenly, the starting point of the twist is raised in height, this starting point is generally a pulley or a spout with or without a guiding funnel, delivering cable on the vertical axis of the tank.
Winding down is traditionally done by human hand, however with heavy cables that may exceed 70 kg/m (kilograms per meter) completely manual coiling down is not possible.
French patent specification number 1 433 701 and its 1st certificate of addition number 88 593 describe a mechanical device for giving assistance in coiling down a cable, the device uses a plurality of pulleys at adjustable spacing which are mounted on a rotating support turning about a the vertical axis of the tank.
This device suffers from drawbacks such as the danger of a heavy cable sagging excessively or even collapsing under its own weight between two successive support points when only a small number of pulleys are used, or such as the need to use the coiling down device during uncoiling as well because of the permanent presence of the said structure on the ground in the center of the tank which impedes natural uncoiling of the cable.
Preferred embodiments of the present invention remedy these drawbacks by providing a semi-automatic machine which conveys a cable via many support points on a deformable structure which enables the cable to be laid in spiral turns of diameter varying in a ratio of up to 1 to 3, and also enabling a cable inlet chute to be moved out of the way to free the cable near the funnel hole, and thus allow the cable to be uncoiled naturally.